JPS60241641A - Flat-type cell - Google Patents

Abstract

PURPOSE:To enhance capacity of a cell as well as to increase sealing strength by providing a ring-shape concave portion at the vertical part of a sealing plate, besides providing a ring-shape convex portion at the side wall part of a positive electrode case and sealing them with a gasket interposed between them. CONSTITUTION:A ring-shape inward-convex portion is formed at the vertical part of the sealing plate 1 of a cell and in consequence, a relatively outward- concave portion of ring-shape is formed where an L-shape gasket 2 is fitted. A ring-shape inward convex portion is formed at the sidw all part of its positive electrode case 3 and a ring-shape inward-convex portion is formed at the bottom part of said case 3 on the extended line of the opening end part of the sealing plate 1, and positive electrode black mix 7, a separator 6 and impregnant 5 are contained in the case. Thus, a button-type silver oxide cell or the like is formed by making the sealing plate 1 in contact with the case 3 and fitting and tightly sealing them at the two places at the side wall part and at bottom part of the positive electrode case 3. Therefore, it is possible to make the cell thin and at the same time, to enhance discharge capacity by increasing the filling amount of active material, as well as to improve liquidtightness by increasing sealing strength.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to improvements in so-called flat batteries such as button-type alkaline batteries and coin-type organic electrolyte batteries.

The structure of conventional examples and their problems In flat batteries, especially thin flat batteries, in order to make them thinner, it is necessary to reduce the thickness of each component, and the sealing strength and internal active material filling are Various methods have been studied for increasing the volume. For example, (1) thinning the sealing plate by switching from a sealing plate with a folded U-shaped part on the periphery to a sealing plate with a horizontal flange; (2) using a substantially vertical sealing plate without a folded part; There is an increase in internal filling volume.

In method (1) above, by using a sealing plate with a horizontal flange, the battery can be made thinner and the strength of the sealing part can be satisfied to some extent, but as shown in Figure 1, the sealing part is The structure occupies a large volume and the amount of active material filled is accordingly small, which is insufficient for improving battery capacity.

In addition, method (2) above uses a sealing plate in a substantially vertical shape as shown in FIG. In particular, if the adhesion between the opening tip of the sealing plate and the gasket is insufficient, the stainless steel that is the base material of the sealing plate will react with the electrolyte at the tip of the sealing plate, generating hydrogen gas and causing leakage. This may cause defects such as battery swelling or, in severe cases, battery rupture.
These methods (1) and (2) all have advantages and disadvantages in sealing strength and battery capacity.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a flat battery that overcomes the above-mentioned conventional drawbacks, has good sealing strength and battery capacity, and is easy to manufacture.

Structure of the Invention The present invention provides an inward annular convex portion and an outward annular concave portion approximately at the center of the vertical portion of the sealing plate, and inwardly moves the side wall portion of the positive electrode case at a position corresponding to the concave portion. The sealing plate is pressed into an annular convex shape, the sealing plate and the side wall of the positive electrode case are fitted tightly together, and the bottom of the positive electrode case, which is an extension of the opening end of the sealing plate, is pressed inward in the annular convex shape. .

According to this configuration, since the proportion occupied by the sealing portion is low, it is possible to increase the amount of active material filled. Furthermore, since the positive electrode case is tightly sealed at two points, the side wall and the bottom, the sealing strength is excellent and the battery performance is improved.

, Description of Examples The present invention will be explained in detail below.

FIG. 3 shows a button-type silver oxide battery. In the figure, 1 is N
A sealing plate made of i-3US-Cu three-layer clad material,
It has an outer diameter of 5.6 mm and has an annular convex portion inwardly and a relatively annular concave portion outwardly on the vertical portion. A gasket 2 having a generally inverted cross-section is fitted around its periphery, and the sealing plate to which the gasket is combined contains frozen zinc and CM.
A negative electrode mixture 4 containing G, a gelling agent such as sodium polyacrylate, and an electrolyte is located. Furthermore, an impregnating material 6 made of nylon nonwoven fabric, etc., a separator 6 made of a crosslinked polyethylene film, etc., and a positive electrode mixture 7 made of a mixture of silver oxide, graphite, etc.
is separated from the negative electrode mixture 4, and the positive electrode case side wall portion of the positive electrode case 3, which serves as both the container and the positive electrode terminal, is pressed inward to form an annular projection at a position corresponding to the annular projection on the vertical portion of the sealing plate. The batten and the side wall of the positive electrode case are brought into close contact with each other, and the bottom of the positive electrode case is located on the extension line of the opening end of the sealing plate, that is, from the center of the case.
．． The seal was sealed by pressing inward in the form of an annular convex portion at position 8H. A silver oxide battery 5R621 according to the configuration of the present invention is shown in Figure 1, B is a battery with the configuration shown in Figure 1 having a conventional horizontal flange, and Figure 2 shows a battery having only a vertical part of the sealing plate and no folded part. A battery having the configuration shown in FIG.

Battery Negative electrode filling amount Discharge capacity Leakage resistance (person) 2
3,0jlF 1 6.3mAH0150(B>1
9.011%+13. ts mAHo/s.

(C) 22,011g 15.6mAH 10150 However, the above discharge capacity is calculated from a constant resistance discharge of 30Ω, and the leakage resistance is determined by visually observing the leakage state after storage for 2000 hours at 45°C and 90% temperature and humidity. It shows the number of leaks during 6 inspections.

In addition, 6 out of 60 batteries C had blistering, and the other batteries B did not have any blisters.

Although the examples have been shown above using button-type silver oxide batteries, similar effects were obtained with button-type alkaline manganese batteries and organic electrolyte batteries.

Effects of the Invention As is clear from the above examples, the battery of the present invention has the following effects:
It has excellent sealing strength, good leakage resistance, can be filled with a large amount of active material, and has excellent discharge capacity.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a conventional button-type silver oxide battery, FIG. 2 is a vertical cross-sectional view of a conventional button-type silver oxide battery, and FIG. 3 is a vertical cross-section of a button-type silver oxide battery according to an embodiment of the present invention. Show the diagram. 1... Sealing plate, 2... Gasket, 3...
・Positive electrode case, 4... Negative electrode mixture, 6...
Impregnation material, 6... Separator, 7... Positive electrode mixture.

Claims (1)

[Claims] Arrange the positive electrode mixture, separator, and impregnating material in order from the bottom inside the positive electrode case, and fit a gasket with an approximately inverted U-shaped cross section to the periphery of the sealing plate that contains the negative electrode mixture and has an approximately inverted U-shaped cross section. The vertical part of the sealing plate has an annular protrusion inwardly and an annular concave outward in substantially the center of the vertical part of the sealing plate, and a side wall of the positive electrode case at a position corresponding to the concave part. The sealing plate and the side wall of the positive electrode case are fitted tightly together by pressing inward in an annular convex shape, and the bottom of the positive electrode case, which is an extension of the opening end of the sealing plate, is pressed inward in an annular convex shape. A flat battery characterized by: